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Background and purposeThe effect of exposing the developing brain of a high school football player to subconcussive impacts during a single season is unknown. The purpose of this pilot study was to use diffusion tensor imaging to assess white matter changes during a single high school football season, and to correlate these changes with impacts measured by helmet accelerometer data and neurocognitive test scores collected during the same period.Materials and methodsSeventeen male athletes (mean age, 16 ± 0.73 years) underwent MR imaging before and after the season. Changes in fractional anisotropy across the white matter skeleton were assessed with Tract-Based Spatial Statistics and ROI analysis.ResultsThe mean number of impacts over a 10-g threshold sustained was 414 ± 291. Voxelwise analysis failed to show significant changes in fractional anisotropy across the season or a correlation with impact frequency, after correcting for multiple comparisons. ROI analysis showed significant (P < .05, corrected) decreases in fractional anisotropy in the fornix-stria terminalis and cingulum hippocampus, which were related to impact frequency. The effects were strongest in the fornix-stria terminalis, where decreases in fractional anisotropy correlated with worsening visual memory.ConclusionsOur findings suggest that subclinical neurotrauma related to participation in American football may result in white matter injury and that alterations in white matter tracts within the limbic system may be detectable after only 1 season of play at the high school level.

Stress fractures, particularly those in the lower extremity, are disabling and time-consuming injuries commonly seen in athletes. A stress fracture of the posterior talus is rare and presents with signs and symptoms similar to those of soft-tissue injuries in the rear foot. This case study involves a Division-I collegiate female field-hockey athlete who developed a stress reaction in her posterior talus approximately 6 weeks after sustaining a mild eversion ankle sprain. Her chief complaint was pain with forceful plantar flexion during running and cutting. Clinicians must be cautious when an athlete presents with posterior foot pain, being sure to properly assess and rule out differential diagnoses such as tendinitis, os trigonal fracture, and muscle strains. This athlete was able to remain weight bearing during healing, so her rehabilitation protocol allowed for a variety of exercise options. [ABSTRACT FROM AUTHOR]

BACKGROUND: Strength training is considered a strategy for anterior cruciate ligament injury prevention. Little is known about the contribution of strength training to knee and hip biomechanics. HYPOTHESIS: Lower extremity muscle strength training alters knee and hip biomechanics during a stop-jump task. STUDY DESIGN: Controlled laboratory study. METHODS: Knee and hip 3-dimensional kinematic and kinetic data were collected for 66 female recreational athletes (33 intervention and 33 control) while performing 3 stop-jump tasks before and after completing a 9-week strength-training program targeting the quadriceps, hamstrings, gluteus medius, and gluteus maximus (intervention) or a 9-week period of no strength training (control). Maximum voluntary isometric contraction strength data were also collected for each subject before the stop-jump tasks in each data collection session. Knee and hip joint angles as well as resultant forces and moments were calculated. RESULTS: The intervention group increased in strength (P < .001 for all muscles). No significant differences were observed in knee and hip kinematics and kinetics between groups before and after the strength-training protocol. CONCLUSIONS: Strength training alone does not alter knee and hip kinematics and kinetics in female recreational athletes. Further research is needed to determine the effect of strength training in combination with other intervention methods on lower extremity biomechanics. CLINICAL RELEVANCE: Strength training as a single intervention method may not be sufficient to reduce the risk of noncontact anterior cruciate ligament injury in female recreational athletes. [ABSTRACT FROM AUTHOR]

CONTEXT: Computerized neuropsychological testing is used in athletics; however, normative data on an athletic population are lacking. OBJECTIVE: To investigate factors, such as sex, SAT score, alertness, and sport, and their effects on baseline neuropsychological test scores. A secondary purpose was to begin establishing preliminary reference data for nonsymptomatic collegiate athletes. DESIGN: Observational study. SETTING: Research laboratory. PATIENTS OR OTHER PARTICIPANTS: The study population comprised 327 National Collegiate Athletic Association Division I athletes from 12 men's and women's sports. MAIN OUTCOME MEASURE(S): Athletes were baseline tested before their first competitive season. Athletes completed demographics forms and self-reported history of concussion (1 or no concussion and 2 or more concussions) and SAT scores (<1000, 1000 to 1200, and >1200). The 108 women had a mean age of 18.39 +/- 0.09 years, height of 167.94 +/- 0.86 cm, and mass of 62.36 +/- 1.07 kg. The 219 men had a mean age of 18.49 +/- 0.07 years, height of 183.24 +/- 1.68 cm, and mass of 88.05 +/- 1.82 kg. Sports participation included women's soccer, lacrosse, basketball, and field hockey; men's football, soccer, lacrosse, and wrestling; and women's and men's track and cheerleading. We used the Automated Neuropsychological Assessment Metrics (Army Medical Research and Materiel Command, Ft Detrick, MD) and measured throughput scores (the number of correct responses per minute) as the dependent variable for each subtest, with higher scores reflecting increased speed and accuracy of responses. Subsets included 2 simple reaction time (SRT) tests, math processing (MTH), Sternberg memory search (ST6), matching to sample pairs (MSP), procedural reaction time (PRO), code digit substitution (CDS), and the Stanford sleep scale Likert-type score. RESULTS: Women scored better than men on the ST6 (P < .05), while men scored significantly better than women on the SRT and MSP tests. The highest-scoring SAT group performed better than other SAT groups on selected subtests (SRT, MTH, ST6, MSP, and CDS) (P < .05), and athletes tested during their season were more likely to score lower on the alertness scale (chi(2) (2)[n = 322] = 11.32, P = .003). The lowest alertness group performed worse on the MSP and CDS subtests (P < .05). No differences were found between the group with a history of 1 or no concussion and the group with a history of 2 or more concussions (P > .05). CONCLUSIONS: Performance on computerized neuropsychological tests may be affected by a number of factors, including sex, SAT scores, alertness at the time of testing, and the athlete's sport. To avoid making clinical misinterpretations, clinicians should acknowledge that individual baselines vary over time and should account for this variation. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To examine effects of preseason baseline headache and posttraumatic headache (PTH) on neurocognitive function. DESIGN: Retrospective repeated measures study with headache groups formed regarding baseline headache score (0 = negative headache; 1-6 = positive headache) and day 1 postinjury headache score (0 = no headache; 1-2 = mild headache; 3-6 = moderate-severe headache). SETTING: Clinical athletic training setting and sports medicine research laboratory. PARTICIPANTS: High-school and collegiate athletes with a concussion. INDEPENDENT VARIABLES: Preseason baseline headache, PTH, test-day. MAIN OUTCOME MEASURES: A Graded Symptom Checklist (GSC) was used to assess symptoms. The Automated Neuropsychological Assessment Metrics (ANAM) and the Standardized Assessment of Concussion (SAC) were used to assess neuropsychological function and mental status. The Balance Error Scoring System (BESS) was used to assess postural stability. RESULTS: Both baseline headache groups displayed a higher symptom endorsement and higher symptom severity at day 1 postinjury and improved by day 7 postinjury. The positive headache group reported an even greater increase in symptom severity and presence (P < 0.05). ANAM revealed deficits in both groups 1 day postinjury. All PTH headache groups displayed a difference in symptom number and severity with the increase being magnified by headache severity (P < 0.05). Individuals reporting moderate-severe PTH displayed increased deficits subacutely but improved by 5-7 days postinjury on overall neuropsychological performance, reaction time, and working memory (P < 0.05). Deficits were observed for all ANAM measures except simple reaction time 1 (SRT 1) and match to sample subacutely and improved over time (P < 0.05). The SAC yielded an interaction (P < 0.05) for baseline headache. The BESS yielded no significant findings. CONCLUSIONS: Clinicians should consider headache when assessing concussion and during preseason baseline assessments because headache may affect symptom presence and other clinical measures of concussion. [ABSTRACT FROM AUTHOR]

Context: The return-to-play decision after sport-related cerebral concussion depends in part on knowing when an athlete has fully recovered postural control after injury. Objective: To describe the postconcussion recovery of postural control using approximate entropy (ApEn), a regularity statistic from nonlinear dynamics. Design: Retrospective case series analysis. Setting: Sports medicine research laboratory. Patients or Other Participants: Collegiate athletes from whom center-of-pressure and symptom data were collected at preseason, less than 48 hours after injury, and 48 to 96 hours after injury. Main Outcome Measure(s): Approximate entropy values reflecting the amount of randomness contained in center-of-pressure oscillations were calculated for anterior-posterior (AP) and medial-lateral (ML) time series. Equilibrium scores reflecting the amplitude of center-of-pressure AP oscillations were used to indicate postural stability. The number and severity of symptoms were described. Results: Compared with the healthy preseason state, ApEn values for the AP and ML time series generally declined immediately after injury in both steady and unsteady injured athletes. At 48 to 96 hours after injury, ApEn values for the ML time series remained significantly depressed (mean difference compared with preseason = -0.268, standard error = 0.072), even among athletes whose initial postural instability had resolved. We found few significant relationships between changes in ApEn values and changes in symptoms before and after injury. Conclusions: The effects of cerebral concussion on postural control appear to persist for longer than 3 to 4 days, even among athletes with no signs of unsteadiness. Our results may reflect changes in neurophysiologic or mechanical constraints on postural control. Approximate entropy provides a theoretically distinct, valuable measurement alternative that may prove useful for reducing uncertainty in the return-to-play decision. [ABSTRACT FROM AUTHOR]

Context: Athletic trainers surveyed in 1999 demonstrated little consensus on the use of concussion grading scales and return-to-play criteria. Most relied on clinical examination or symptom checklists to evaluate athletes with concussion. Objective: To investigate the current trends of certified athletic trainers in concussion assessment and management. Design: Subjects were invited to participate in a 32-question Internet survey. Setting: An Internet link to the survey was e-mailed to the subjects. Patients or Other Participants: A total of 2750 certified athletic trainers and members of the National Athletic Trainers' Association were randomly e-mailed and invited to participate. Main Outcome Measure(s): Survey questions addressed topics including years of certification, number of concussions evaluated each year, methods of assessing concussion, and guidelines used for return to play. Compliance with the recent position statement of the National Athletic Trainers' Association on sport-related concussion was also evaluated. Results: Certified athletic trainers averaged 9.9 +/- 7.3 years of certification and evaluated an average of 8.2 +/- 6.5 concussions per year. To assess concussion, 95% reported using the clinical examination, 85% used symptom checklists, 48% used the Standardized Assessment of Concussion, 18% used neuropsychological testing, and 16% used the Balance Error Scoring System. The most frequently used concussion grading scale and return-to-play guideline belonged to the American Academy of Neurology (30%). When deciding whether to return an athlete to play, certified athletic trainers most often used the clinical examination (95%), return-to-play guidelines (88%), symptom checklists (80%), and player self-report (62%). The most important tools for making a return-to-play decision were the clinical examination (59%), symptom checklists (13%), and return-to-play guidelines (12%). Only 3% of certified athletic trainers surveyed complied with the recent position statement, which advocated using symptom checklists, neuropsychological testing, and balance testing for managing sport-related concussion. Conclusions: Our findings suggest that only a small percentage of certified athletic trainers currently follow the guidelines proposed by the National Athletic Trainers' Association. Various assessment methods and tools are currently being used, but clinicians must continue to implement a combination of methods and tools in order to comply with the position statement. [ABSTRACT FROM AUTHOR]

Context: Factors contributing to functional ankle instability may cause individuals with the condition to land from a jump differently than those with stable ankles. Objective: To determine stabilization time differences during single-leg jump landings between stable and unstable ankle groups and to report the reliability and precision of time-to-stabilization measures. Design: A mixed design with 1 between factor (ankle group) and 1 within factor (direction) was used to analyze the comparison between our 10 subjects with functional ankle instability and 10 subjects with stable ankles. Time to stabilization (seconds) was the dependent measure. Reliability for time-to-stabilization measures of our 12 additional subjects with stable ankles were assessed using intraclass correlation coefficients (ICC 2,7). Standard errors of measurements were also calculated for time-to-stabilization measures. Setting: Sports medicine research laboratory. Patients or Other Participant(s): Ten subjects with functional ankle instability who reported at least 2 sprains and 'giving way' sensations at their ankles constituted the functional ankle instability group. Ten subjects without a history of ankle sprain injury served as healthy subjects. Twelve additional healthy subjects participated in the reliability study. Intervention(s): Subjects performed a jump-landing test, which required them to jump 50% to 55% of their maximum vertical jump height and then land on a single leg on a force plate. After landing, they stabilized quickly and remained as motionless as possible in a single-leg stance for 20 s. Main Outcome Measure(s): Anterior-posterior and medial/ lateral vibration magnitude curve fit time-to-stabilization. Results: Time to stabilization was longer for the functional ankle instability group (1.98 +/- 0.81 s) than for the stable ankle group (1.45 +/- 0.30 s) (P < .05). Reliability (standard error of the measurement) values for anterior/posterior and medial/lateral time-to-stabilization were 0.79 (0.15 s) and 0.65 (0.26 s), respectively. Conclusions: Time to stabilization was longer for subjects with functional ankle instability than subjects with stable ankles. The ankle instability may have impaired the subjects' ability to stabilize after a single-leg jump landing. Reliabilities and standard errors of the measurements of time-to-stabilization measures were moderate and low, respectively. [ABSTRACT FROM AUTHOR]

Background: Gender differences in lower extremity motion patterns were previously identified as a possible risk factor for non-contact anterior cruciate ligament injuries in sports.Hypothesis: Gender differences in lower extremity kinematics in the stop-jump task are functions of age for youth soccer players between 11 and 16 years of age.Study Design: Descriptive laboratory study.Methods: Three-dimensional videographic data were collected for 30 male and 30 female adolescent soccer players between 11 and 16 years of age performing a stop-jump task. The age effects on hip and knee joint angular motions were compared between genders using multiple regression analyses with dummy variables.Results: Gender and age have significant interaction effects on standing height (P = .00), body mass (P = .00), knee flexion angle at initial foot contact with the ground (P = .00), maximum knee flexion angle (P = .00), knee valgus-varus angle (P = .00), knee valgus-varus motion (P = .00), and hip flexion angle at initial foot contact with the ground (P = .00).Conclusion: Youth female recreational soccer players have decreased knee and hip flexion angles at initial ground contact and decreased knee and hip flexion motions during the landing of the stop-jump task compared to those of their male counterparts. These gender differences in knee and hip flexion motion patterns of youth recreational soccer players occur after 12 years of age and increase with age before 16 years.Clinical Relevance: The results of this study provide significant information for research on the prevention of noncontact anterior cruciate ligament injuries. [ABSTRACT FROM AUTHOR]

BACKGROUND: Anterior cruciate ligament injury prevention programs have used videotapes of jump-landing technique as a key instructional component to improve landing performance. HYPOTHESIS: All videotape feedback model groups will increase knee flexion angles at initial contact and overall knee flexion motion and decrease peak vertical ground reaction forces and peak proximal anterior tibial shear forces to a greater extent than will a nonfeedback group. The secondary hypothesis is that the videotape feedback using the combination of the expert and self models will create the greatest change in each variable. STUDY DESIGN: Controlled laboratory study. METHODS: Knee kinematics and kinetics of college-aged recreational athletes randomly placed in 3 different videotape feedback model groups (expert only, self only, combination of expert and self) and a nonfeedback group were collected while participants performed a basketball jump-landing task on 3 testing occasions. RESULTS: All feedback groups significantly increased knee angular displacement flexion angles [F(6,70) = 8.03, P = .001] and decreased peak vertical ground reaction forces [F(6,78) = 2.68, P = .021] during performance and retention tests. The self and combination groups significantly increased knee angular displacement flexion angles more than the control group did; the expert model group did not change significantly more than the control group did. All feedback groups and the nonfeedback group significantly reduced peak vertical forces across performance and retention tests. There were no statistically significant changes in knee flexion angle at initial ground contact (P = .111) and peak proximal anterior tibial shear forces (P = .509) for both testing sessions for each group. CONCLUSION: The use of self or combination videotape feedback is most useful for increasing knee angular displacement flexion angles and reducing peak vertical forces during landing. CLINICAL RELEVANCE: The use of self or combination modeling is more effective than is expert-only modeling for the implementation of instructional programs aimed at reducing the risk of jump-landing anterior cruciate ligament injuries. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To determine static and dynamic postural stability differences between functional ankle instability and stable ankle groups. DESIGN: Subjects were required to balance on a single leg and remain motionless for 20 seconds. After completing 3 trials, they performed a jump-landing test, which required them to jump 50% to 55% of their maximum vertical jump height. They landed on a single leg, stabilized quickly, and remained motionless for 20 seconds. SETTING: Sports Medicine Research Laboratory. PARTICIPANTS: Subjects with functional ankle instability (n = 14) who reported at least 2 sprains and 'giving way' sensations at their ankle joint within the year prior to testing. Fourteen subjects with no history of ankle sprain injury were matched to subjects with functional ankle instability. MAIN OUTCOME MEASURES: Anterior/posterior and medial/lateral mean sway quantified static postural stability during single-leg stance. Dynamic postural stability was quantified with anterior/posterior and medial/lateral time to stabilization during single-leg jump landing. RESULTS: Mean sway was not significantly different between groups in the anterior/posterior (P = 0.28) and medial/lateral (P = 0.65) directions. The functional ankle instability group took significantly longer to stabilize in the anterior/posterior (3.27 +/- 0.72 seconds vs. 2.33 +/- 0.33 seconds; P < 0.001) and medial/lateral (2.48 +/- 0.50 seconds vs. 2.00 +/- 0.65 seconds; P = 0.04) directions. CONCLUSIONS: Individuals with functional ankle instability took significantly longer to stabilize than individuals with stable ankles after a single-leg jump landing. Differences between groups were not detected with mean sway measured during single-leg stance. [ABSTRACT FROM AUTHOR]

Objective: Postural stability and neuropsychological testing are gradually becoming integral parts of postconcussion assessment in athletes. Clinicians, however, sometimes question the viability of instituting preseason baseline testing and the value of these results in making return-to-play decisions. Our purpose was to examine the course of recovery on various postural stability and neuropsychological measures after sport-related concussion. A secondary goal was to determine if loss of consciousness and amnesia, both of which are heavily weighted in most of the concussion classification systems, affect the rate of recovery.Design and Setting: All subjects underwent a battery of baseline postural stability and neuropsychological tests before the start of their respective seasons. Any athletes subsequently injured were followed up at postinjury days 1, 3, and 5. Matched control subjects were assessed using the same test battery at the same time intervals.Subjects: We studied 36 Division I collegiate athletes who sustained a concussion and 36 matched control subjects.Measurements: We assessed postural stability using the Sensory Organization Test on the NeuroCom Smart Balance Master System and the Balance Error Scoring System. Neurocognitive functioning was measured with several neuropsychological tests: Trail-Making Test, Wechsler Digit Span Test, Stroop Color Word Test, and Hopkins Verbal Learning Test.Results: Injured subjects demonstrated postural stability deficits, as measured on both the Sensory Organization Test and Balance Error Scoring System. These deficits were significantly worse than both preseason scores and matched control subjects' scores on postinjury day 1. Only the results on the TrailMaking Test B and Wechsler Digit Span Test Backward resulted in a logical recovery curve that could explain lowered neuropsychological performance due to concussive injury. Significant differences were revealed between the control and injured groups at day 1 postinjury, but a significant decline between baseline and postinjury scores was not demonstrated. Loss of consciousness and amnesia were not associated with increased deficits or slowed recovery on measures of postural stability or neurocognitive functioning.Conclusions: Athletes with cerebral concussion demonstrated acute balance deficits, which are likely the result of not using information from the vestibular and visual systems effectively. Neurocognitive deficits are more difficult to identify in the acute stages of concussion, although concentration, working memory, immediate memory recall, and rapid visual processing appear to be mildly affected. More research is necessary to determine the best neuropsychological test battery for assessing sport-related concussion. [ABSTRACT FROM AUTHOR]

Objective: To present the case of a stress fracture of the eighth rib in a female collegiate rower.Background: A female collegiate rower experienced severe pain in her chest, increasing with movement, deep breathing, and erect posture. No acute mechanism of injury was apparent. The team physician diagnosed a rib stress reaction based on clinical examination. The athlete rested for 2 days and then was able to resume rowing workouts. Five months later, she experienced the same sharp pain, with the diagnosis and treatment being the same. The athlete was able to compete in the championships 3 weeks later. At the end of the season, a bone scan revealed a stress fracture of the eighth rib. The athlete rested for 3 weeks and then returned to activity.Differential Diagnosis: Intercostal muscle strain, serratus anterior muscle strain.Treatment: Active rest, involving pain-free cardiovascular workouts and weight training, cessation of rowing until the athlete was asymptomatic, strengthening of dynamic support structures, and analgesic modalities.Uniqueness: Most stress fractures occur in the lower extremity. Those that do occur in the rib cage most often involve the first rib. A limited number of published works have addressed stress fractures to the remaining ribs; of these, posterior and posterolateral fracture sites are most often reported. This case is unique in that the fracture site was on the anterolateral aspect of the eighth rib.Conclusions: Stress fractures are thought to result from a variety of causes, including muscular fatigue, sudden changes in training intensity or duration, and microtrauma to bone at the muscular origin and insertion sites ('wear-and-tear' theory). In addition, hormonal factors in women can predispose an athlete with amenorrhea to a decrease in bone mineral content. Athletic trainers should be aware of these potential causes and focus on the prevention of stress fractures. [ABSTRACT FROM AUTHOR]

Objective: To test whether performance on 5 cognitive tests administered in a controlled clinical environment differed compared with administration in an uncontrolled sideline environment. Additionally, we investigated the effect of testing environment order on the learning effect for each cognitive test. Design and Setting: Athletes were assessed on 2 test occasions (8 +/- 2 days apart), once in a sports medicine research laboratory and once on a lacrosse practice field site. Subjects: A total of 59 Division I collegiate student-athletes participated in this study. Measurements: Normative data were collected on 5 cognitive tests (Stroop Test, Trail-Making Test part A, Trail-Making Test part B, Wechsler Digit-Span Forward Test, and Digit-Span Backward Test). Results: An independent-samples t test for environment difference on test day 1 revealed no significant differences between tests performed in the controlled environment and those performed in the uncontrolled environment. A repeatedmeasures analysis of variance test revealed a significant learning effect for all 5 tests, as subjects tended to improve approximately 11 points on the Stroop Test, 3 seconds on the Trail-Making A Test, 7 seconds on the Trail-Making B Test, and 1 point each on the Wechsler Digit Span Forward and Backward Tests. A paired-samples t test using delta scores (first test minus second test), sorted by order of testing environment, revealed a significant difference for the Stroop Test, but not for the remaining cognitive tests. Conclusions: There appears to be no difference in cognitive testing performance completed in a controlled clinical environment versus that performed in an uncontrolled sideline environment. This finding suggests that clinicians can administer cognitive tests to athletes with mild head injuries in uncontrolled sideline environments and expect valid results. Thus, clinicians can more thoroughly evaluate mildly head-injured athletes during the most crucial period after injury so that a safe return-to-play decision can be based on quantifiable, objective data. [ABSTRACT FROM AUTHOR]

Objective: Although force-platform measures of postural stability provide objective information concerning mild head injury (MHI) resolution, their application has remained limited due to the high costs and impracticality for sideline use. Therefore, we investigated the efficacy of a clinical balance testing procedure for the detection of acute postural stability disruptions after MHI. Design and Setting: We used a posttest control group design with repeated measures. Postural stability was tested at 3 postinjury time intervals (days 1, 3, and 5) using 2 procedures in a sports medicine laboratory: 1) a clinical balance battery consisting of 3 stances (double leg, single leg, and tandem) on 2 surfaces (firm and foam), and 2) the Sensory Organization Test using a sophisticated force-platform system. Subjects: Sixteen MHI and 16 matched control subjects participated in this study. Measurements: We measured performance with the Balance Error Scoring System for each of the clinical balance tests and the NeuroCom Smart Balance Master for Sensory Organization Testing. Results: We found significantly higher postural instability in the MHI subjects revealed through the clinical test battery, with the 3 stances on the foam surface eliciting significant differences through day 3 postinjury. Results of the Sensory Organization Test revealed significant group differences on day 1 postinjury. Conclusions: Our results revealed that the Balance Error Scoring System may be a useful clinical procedure to assist clinicians in making return-to-play decisions in athletes with MHI in the absence of force-platform equipment. [ABSTRACT FROM AUTHOR]

Objective: To examine the effects of fatigue on proprioception and neuromuscular control of the shoulder. Design and Setting: Subjects were randomly assigned to either an experimental group or control group. Subjects were tested using either the active angle-reproduction or the singlearm dynamic stability test. The subjects were then fatigued using a dynamometer performing continuous, concentric rotation exercises of the shoulder. Once fatigued, the subjects were posttested using the same test. One week later, the subjects returned and were pretested, fatigued, and posttested using the other test. Subjects: Thirty-two college-age (18 to 25 years) subjects (16 males, 16 females) with no history of glenohumeral instability or upper extremity injury volunteered for this study. Measurements: Absolute angular error was measured using an electrogoniometer present within the isokinetic dynamometer, while sway velocity was measured using a force-plate system. Results: Repeated-measures analysis of variance revealed a significant difference between the pretest and posttest values for absolute angular error in the experimental group, whereas no significant difference was revealed between pretest and posttest sway velocity for either the control or experimental group. Conclusions: Fatigue of the internal and external rotators of the shoulder decreased proprioception of the shoulder, while having no significant effect on neuromuscular control. [ABSTRACT FROM AUTHOR]

Objective: To present the case of a 20-year-old collegiate wrestler who suffered from atypical chest pains and syncope after rigorous exercise, dehydration, and ingestion of a metabolic stimulant. Background: As a result of pressure to obtain a lower body weight for competition, wrestlers often pursue practices to lose a substantial amount of weight in a short period of time. These practices include rigorous exercise, starvation, dehydration, laxatives, diuretics, and over-the-counter stimulants. Our case involves an athlete who ingested a metabolic stimulant containing ma huang (ephedrine) and suffered from syncope and atypical chest pains during a bout of rigorous exercise and dehydration to lose weight for competition. Differential Diagnosis: Hypertrophic cardiomyopathy, electrolyte imbalance, drug overdose, traumatic head injury, myocardial infarction, syncope. Treatment: The emergency medical services transported the athlete to the emergency room, and he was hospitalized for 2 days. After discharge, the team physician counseled the athlete in the dangers of metabolic stimulants and excessive weight-loss techniques. Uniqueness: This case is unique because it presents an athlete who ingested an over-the-counter stimulant to lose weight and suffered from syncope and atypical chest pains during a bout of rigorous exercise and dehydration. Conclusions: Athletic trainers must understand not only the dangers of excessive weight loss, but also the dangers of using unregulated ephedrine-containing stimulants to aid in weight loss. [ABSTRACT FROM AUTHOR]

Objective: To examine the efficacy of 3 different types of injury support systems (standard elastic wrap with horseshoe, Aircast Sport Stirrup, and Omni Multiphase orthosis) used in treating acute inversion ankle sprains. Subjects: We recruited 30 physically active college-aged subjects who had sustained a grade 1+ or 2 lateral ankle sprain within the previous 24 hours for the study. Design and Setting: Subjects were randomly placed into one of 3 groups, the first treated with standard elastic wrap with horseshoe, the second with an Aircast Sport Stirrup, and the third with an Omni Multiphase orthosis. Subjects reported to the athletic training room on days 1, 2, 3, 5, and 7 postinjury. Measurements: We assessed subjects for ankle volume, functional performance, and self-perception of symptoms during the 5 postinjury assessments. Results: We found no significant differences among the 3 groups on measures of volume, level of function, and self-perception of symptoms. Conclusions: Our results suggest that none of these methods is superior to the others for reducing swelling, restoring function, or relieving symptoms during the acute management of lateral ankle sprains. [ABSTRACT FROM AUTHOR]

Objective: To provide normal data for comparison with objective measures of an athlete's cognitive ability after mild head injury (MHI). Subjects: Seventy-two Division I college athletes. Design and Setting: Athletes were assessed on three test dates (two days apart) in a sports medicine research laboratory. Measurements: Normative data were collected on four cognitive tests (Hopkins Verbal Learning Test, Stroop Test, Reitan Trail-Making Tests, and Wechsler Digit Span Tests). Results: A repeated-measures analysis of variance revealed significant learning effects on all tests except the Hopkins Verbal Learning Test. A high correlation was noted between the Stroop and the Trail-Making Tests. Conclusions. These normative data can be used as comparisons to provide an objective measure of an athlete's cognitive ability following MHI. By adding this test battery to the athlete's other physical and neurologic tests, the decision to return an athlete to competition after MHI can be made with greater confidence and with less risk of reinjury. [ABSTRACT FROM AUTHOR]

Objective: Athletic trainers and team physicians are often faced with the dilemma of when to return athletes to participation following mild head injury. Unfortunately, clinicians rarely have quantitative information on which to base their decisions. The purpose of this investigation was to identify postural stability changes in athletes with acute mild head injury. Design and Setting: High school and college male athletes were prescreened for postural stability before the start of their season. Subjects suffering injury during the season returned for testing on days 1, 3, 5, and 10 following injury, and 1 month postseason. Control subjects were selected for comparisons. Subjects: Ten prescreened subjects (age = 17.4 +/- 2.2 yr; ht = 183.8 +/- 8.1 cm; wt = 87.7 +/- 17.3 kg) returned for testing following an injury. Ten matched control subjects (age = 18.6 +/- 2.6 yr; ht = 185.7 +/- 6.7 cm; wt = 84.5 +/- 19.5 kg) were selected for comparisons. Additionally, nine subjects (eight male and one female) (age = 19.9 +/- 4.2 yr; ht = 182.3 +/- 10.9 cm; wt = 89.6 +/- 25.2 kg) who had sustained a mild head injury from other varsity sports teams were recruited. Nine matched controls (age = 22.1 +/- 3.3 yr; ht = 181.0 +/- 9.9 cm; wt = 84.9 +/- 25.6 kg) were again utilized. Measurements: Sway index and center of balance were measured using the Chattecx Balance System during three eye conditions and three surface conditions for all subjects. Results: Repeated measures analyses of variance (ANOVA) for each prescreened subject's sway index revealed significant differences between injured subjects and control subjects on day 1 postinjury as compared with the prescreening and/or subsequent tests. The analysis for sway index and center of balance inclusive of all 19 subjects with mild head injury and all 19 control subjects demonstrated increased postural sway compared with control subjects on day 1 postinjury during all platform conditions, and on day 3 during the foam platform condition. The analysis for center of balance using the same subjects revealed that injured subjects maintained their center of balance farther away on day 1 postinjury compared with subsequent tests to < .05). Conclusions: These findings suggest that computerized dynamic posturography is a useful tool in objectively assessing postural stability in subjects with mild head injuries. Subjects with mild head injury appear to demonstrate impaired postural stability 1 to 3 days following injury. This information should aid clinicians in determining when an athlete can safely return to participation. [ABSTRACT FROM AUTHOR]

Objective: To review the diagnostic tests and investigations used in the management of sports concussion, in the adult and paediatric populations, to (a) monitor the severity of symptoms and deficits, (b) track recovery and (c) advance knowledge relating to the natural history and neurobiology of the injury.Design: Qualitative literature review of the neuroimaging, balance testing, electrophysiology, blood marker and concussion literature.Intervention: PubMed and Medline databases were reviewed for investigations used in the management of adult and paediatric concussion, including structural imaging (computerised tomography, magnetic resonance imaging, diffusion tensor imaging), functional imaging (single photon emission computerised tomography, positron emission tomography, functional magnetic resonance imaging), spectroscopy (magnetic resonance spectroscopy, near infrared spectroscopy), balance testing (Balance Error Scoring System, Sensory Organization Test, gait testing, virtual reality), electrophysiological tests (electroencephalography, evoked potentials, event related potentials, magnetoencephalography, heart rate variability), genetics (apolipoprotein E4, channelopathies) and blood markers (S100, neuron-specific enolase, cleaved Tau protein, glutamate).Results: For the adult and paediatric populations, each test has been classified as being: (1) clinically useful, (2) a research tool only or (3) not useful in sports-related concussion.Conclusions: The current status of the diagnostic tests and investigations is analysed, and potential directions for future research are provided. Currently, all tests and investigations, with the exception of clinical balance testing, remain experimental. There is accumulating research, however, that shows promise for the future clinical application of functional magnetic resonance imaging in sport concussion assessment and management. [ABSTRACT FROM AUTHOR]

Objective: Although the incidence of catastrophic cervical spine injury in sport has been significantly reduced over the past 3 decades, the injury warrants continued attention because of the altered quality of life that often accompanies such an injury. The purpose of our literature review was to provide athletic trainers with an understanding of the mechanisms, anatomical structures, and complications often associated with sport-related cervical spine injury. We also present the most current recommendations for management and treatment of these potentially catastrophic injuries. Data Sources: A review of the most pertinent literature between 1970 and 2005 was conducted using MEDLINE and the search terms spinal cord injury, cervical spine injury, neurosurgical trauma, cervical spinal stenosis, and catastrophic spine injury. Data Synthesis: Flexion of the head places the cervical spine into a straight line and prevents the neck musculature from assisting in force absorption. This mechanism is the primary cause of cervical fracture, dislocation, and quadriplegia. The most serious of the syndromes described in the literature involves a complete spinal cord injury with transverse myelopathy. This injury typically results in total loss of spinal function below the level of the lesion. Conclusions/Recommendations: Spinal trauma may result in a variety of clinical syndromes, according to the type and severity of the impact and bony displacement, as well as subsequent secondary insults such as hemorrhage, ischemia, and edema. Athletic trainers should be prepared to promptly recognize these potentially catastrophic injuries and follow the recommendations of the Inter-Association Task Force for the Appropriate Care of the Spine Injured Athlete in managing such injuries. [ABSTRACT FROM AUTHOR]

Objective: To describe 3 measures of incidence used in sports injury epidemiology.Background: To promote safety in sports, athletic trainers must be able to accurately interpret and apply injury data and statistics. Doing so allows them to more efficiently articulate this information to school administrators in recommending increases in medical resources, such as more personnel, better services, and safer facilities and equipment.Description: Using data from a study of high school sports injuries, we review incidence rates, epidemiologic incidence proportions, and clinical incidence. The incidence rate is the number of injuries divided by the number of athlete-exposures and is based on the epidemiologic concept of person-time at risk. It accounts for variation in exposure between athletes and teams and is widely used by researchers. The epidemiologic incidence proportion is the number of injured athletes divided by the number of athletes at risk. It is a valid estimator of average injury risk, yet it is rarely used in sports injury epidemiology to communicate information about such risks to nonscientists. Clinical incidence is a hybrid between the epidemiologic incidence proportion and the incidence rate in that it uses the number of injuries in the numerator but the number of athletes at risk in the denominator. It has been widely used in research on high school football injury but is neither a valid estimator of risk nor a true rate.Advantages: Athletic trainers who understand the causes of and risk factors for sport-related injury are better positioned to make safe return-to-play decisions and decrease the likelihood of reinjury in athletes. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Anecdotal evidence suggests that use of Exercise Sandals results in a number of positive clinical outcomes. However, little research has been conducted to determine their efficacy objectively. Our purposes were to determine the effect of Exercise Sandals on lower leg electromyography (EMG) during activities in the Exercise Sandals and to compare EMG associated with Exercise Sandals with traditional lower extremity rehabilitation exercises. DESIGN AND SETTING: Two within-subjects, repeated-measures designs were used to identify differences in lower extremity EMG: (1) between activities with and without Exercise Sandals and (2) between Exercise Sandals activities and traditional rehabilitation activities. All data were collected in the Sports Medicine Research Laboratory. SUBJECTS: Eighteen subjects involved in rehabilitation using Exercise Sandals for at least 2 weeks within the year before data collection. MEASUREMENTS: Mean EMG amplitudes from the tibialis anterior, peroneus longus, soleus, and lateral gastrocnemius muscles were measured during single-leg stance, side stepping, and 'high knees,' all performed with and without the Exercise Sandals, as well as single-leg stance on a foam surface and T-band kicks in the sagittal and frontal planes. RESULTS: Exercise Sandals increased lower leg EMG activity, particularly in the ankle invertors and evertors. Also, activities involving the Exercise Sandals resulted in EMG activity similar to or exceeding that associated with traditional ankle-rehabilitation exercises. CONCLUSIONS: These results, coupled with the fact that Exercise Sandals are used in a functional closed kinetic chain manner, suggest that they are an effective means of increasing lower extremity muscle activity. [ABSTRACT FROM AUTHOR]

Context: Dehydration and concussion are common in athletic performance. Some experts have speculated that dehydration may negatively influence performance on tests commonly used for concussion assessment. Objective: To determine how the signs and symptoms, neuropsychological performance, and postural stability are affected by dehydration. Design: Repeated-measures design assessing subjects in the euhydrated and dehydrated conditions. Setting: Sports Medicine Research Laboratory. Patients or Other Participants: Twenty-four healthy, male recreational athletes participated in the study. Intervention(s): Subjects participated in 2 counterbalanced sessions (euhydrated and dehydrated) separated by at least 7 days. Subjects were dehydrated using fluid restriction and an exercise task. No direct intervention was provided for the euhydrated condition. Main Outcome Measure(s): We used the Standardized Assessment of Concussion to test mental status, the Automated Neuropsychological Assessment Metrics (ANAM) to evaluate neuropsychological performance, the NeuroCom Sensory Organization Test and Balance Error Scoring System to test postural stability, the Graded Symptom Checklist to assess symptom presence and severity in our participants, and urine specific gravity and body mass to determine hydration status. Results: No differences were noted for the Standardized Assessment of Concussion, total Balance Error Scoring System errors, composite Sensory Organization Test, and composite ANAM scores between conditions. Subjects in the dehydrated condition had significant deterioration in visual memory (t[23] = 2. 130, P < . 001) and fatigue measures (t[23] =-7. 880, P < . 001) as assessed by ANAM. The dehydrated condition resulted in subjects reporting a significantly higher number (t[23] =-8. 585, P < . 001) and severity (t[23] =-7. 673, P < . 001) of symptoms than the euhydrated subjects on the Graded Symptom Checklist. Conclusions: Our results suggest that moderate dehydration (-2. 5 ± 0. 63%) significantly influenced the self-report of symptoms commonly associated with concussion. Dehydration resulted in a deterioration of visual memory and increases in the self-report of fatigue. Despite these findings, dehydration did not affect other neuropsychological and postural stability objective testing measures for concussion. [ABSTRACT FROM AUTHOR]

Context: Establishing psychometric and measurement properties of concussion assessments is important before these assessments are used by clinicians. To date, data have been limited regarding these issues with respect to neurocognitive and postural stability testing, especially in a younger athletic population. Objective: To determine the test-retest reliability and reliable change indices of concussion assessments in athletes participating in youth sports. A secondary objective was to determine the relationship between the Standardized Assessment of Concussion (SAC) and neuropsychological assessments in young athletes. Design: We used a repeated-measures design to evaluate the test-retest reliability of the concussion assessments in young athletes. Correlations were calculated to determine the relationship between the measures. All subjects underwent 2 test sessions 60 days apart. Setting: Sports medicine laboratory and school or home environment. Patients or Other Participants: Fifty healthy young athletes between the ages of 9 and 14 years. Main Outcome Measure(s): Scores from the SAC, Balance Error Scoring System, Buschke Selective Reminding Test, Trail Making Test B, and Coding and Symbol Search subsets of the Wechsler Intelligence Scale for Children were used in the analysis. Results: Our test-retest indices for each of the 6 scores were poor to good, ranging from r = .46 to .83. Good reliability was found for the Coding and Symbol Search tests. The reliable change scores provided a way of determining a meaningful change in score for each assessment. We found a weak relationship (r < .36) between the SAC and each of the neuropsychological assessments; however, stronger relationships (r > .70) were found between certain neuropsychological measures. Conclusions: We found moderate test-retest reliability on the cognitive tests that assessed attention, concentration, and visual processing and the Balance Error Scoring System. Our results demonstrated only a weak relationship between performance on the SAC and the selected neuropsychological tests, so it is likely that these tests assess somewhat different areas of cognitive function. Our correlational findings provide more evidence for using the SAC along with a more complex neuropsychological assessment battery in the evaluation of concussion in young athletes. [ABSTRACT FROM AUTHOR]

Context: Improving postural stability through balance training may prevent ankle sprains. Exercise Sandals may increase the demands placed on ankle muscles during rehabilitation, which could improve postural stability. Objective: To examine the effects of functional balance training, with and without the use of Exercise Sandals, on postural stability in subjects with stable or unstable ankles. Design: Prospective, nonrandomized clinical trial. Setting: Sports medicine research laboratory. Patients or Other Participants: Sixteen subjects with functional ankle instability and 16 subjects with no history of ankle sprains. Intervention(s): Subjects were assigned to an Exercise Sandal functional balance training group or a shoe functional balance training group. Subjects trained 3 times per week for 8 weeks and then performed a single-limb stance posttest. Main Outcome Measure(s): Subjects were required to remain as motionless as possible during a single-limb stance pretest. Anterior-posterior and medial-lateral center-of-pressure excursions were measured. Results: Exercise Sandal balance training improved anterior-posterior postural stability in both ankle groups (P < .05). Both training interventions improved medial-lateral postural stability in stable and unstable ankles (P < .05). Conclusions: Postural stability improved after subjects performed functional balance training programs, both with and without Exercise Sandals. Training with Exercise Sandals might not be any more effective in improving postural stability than performing functional balance training without Exercise Sandals. However, Exercise Sandals did not impair postural stability and, consequently, might serve as an alternative therapy to improve postural stability. [ABSTRACT FROM AUTHOR]